i can't believe what i never realized

.....we met probably 27 years ago now
he was married and i was a very broken version of my self.
he looked at me and i looked at him and from that moment on i thought he walked on water. i don' t know (even to this day) what it was about him but i fell so completely head over heels, from the bottom of my feet to the top of my head in love with him.
I placed no one above him and he could do no wrong. We went out for a number of months and then broke it off (why I wasn't entirely sure).
We kept in contact over the years (26) off and on.
At some points more off .....than on
Even though i married and had a family i still thought of him.
He stayed married and had his family but there was still a yearning to know how each other was doing.
I called him up over a year ago now and we talked for a short time. Next thing I know I was walking out of the door to do some recycling and at that precise second he was driving by my house. I was so totally friggen hooked all over again.  I have lowered my self to do things for him that I would never never do for someone else.  I have let him treat me so utterly awful and I still love him desperately.  What in the hell is wrong with me and just what is it about him that I so need him